No law/no works advocates "credit" the apostle Paul for teaching that God's law is done away. However, notice that Peter says all of Paul's epistles had things in them that people twisted! This happens because people frequently will not take the time to study deeply, and at the same time, lack the humility to admit the truth.
John W. Ritenbaugh
Is the Christian Required to Do Works? (Part One)
Verse 14 mentions peace, yet when Christ returns as the Captain of heaven's armies—as the chapter proclaims—there will be war. The iniquity of the world will be full, and He will fight against those opposed to Him. Peter counsels us to ensure that when He returns, He finds us at peace with Him rather than in opposition.
That may sound obvious, but consider how it might apply. If we are opposed to the requirements of God's law, then we are not at peace with the Lawgiver. If we are angry with God for some reason, we are not at peace. If we disagree with God's reaction or non-reaction or overall management of His creation, then we are not at peace with Him.
There can be as many applications as there are individuals, because wherever carnality exists, a measure of enmity remains (Romans 8:7). Peace with God depends on our trusting Him absolutely with our lives. Only then will we not take His words and actions as being hostile toward us, and we will not be hostile toward Him because we trust Him to have our best interests in mind. If our faith—trust—slips, then peace with God begins to fracture.
Peter observes that some of the things Paul writes are hard to understand and that people tend to use Paul's writings in particular in a destructive way. Even today, Paul is falsely known as a champion of a no-works theology, and his writings are cited to say that God's law has been abolished. Twisting Paul's writings in that way is what will cause destruction, because when the Judge returns, He will use His law as the basis of judgment.
Peter leaves us with these final thoughts:
You therefore, beloved, since you know this beforehand, beware lest you also fall from your own steadfastness, being led away with the error of the wicked; but grow in the grace and knowledge of our Lord and Savior Jesus Christ. (II Peter 3:17-18)
The apostle warns against being deceived by all the things he talks about in this chapter, and his warning probably includes the previous chapter. As the saying goes, “Forewarned is forearmed.” Paul prophesies, though, that some are going to depart from the faith (I Timothy 4:1). We have seen that happen. To keep it from happening to us, Peter counsels us to focus on growing in the grace and knowledge of Jesus Christ. He refers to the completion of the repentance or conversion process and our pursuit of salvation to its conclusion.
Jesus is not delaying His coming. He is giving us time to put our houses in order so that we can respond correctly to the work He has begun in us. As Peter says, “To Him be the glory both now and forever. Amen.”
David C. Grabbe
How Much Longer Do We Have?
Peter ends the epistle with the same thought with which he began: We live in spiritually dangerous times, and the way to stay on the beam is to keep on growing. If we grow, our salvation is assured. God is faithful; He has promised us salvation, and He will give it to us if we are faithful.
Richard T. Ritenbaugh
Do We Have 'Eternal Security'?